Ultrastructural investigations on the cephalic and metameric nuchal organs of Spio cf. filicornis (Polychaeta, Spionidae)

Jelsing, Jacob

doi:10.1007/s00435-002-0060-1

Cited by 13 publications

(22 citation statements)

References 16 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Differences between taxa include the number of ciliated supporting and sensory cells as well as the specific structure of the protective layer. These differences may be autapomorphies for certain taxa, such as the paving-stone-like microvillar cover present in Spionida and Protodrilida (Schlo¨tzer-Schrehardt, 1986;Purschke, 1997;Jelsing, 2002b). The number of sensory cells varies from two in Potamodrilus fluviatilis to several hundred in Polyophthalmus pictus and Armandia polyophthalma (see Purschke, 1997;Purschke & Hessling, 2002).…”

Section: Nuchal Organsmentioning

confidence: 97%

Sense organs in polychaetes (Annelida)

Purschke

2005

Hydrobiologia

151

View full text Add to dashboard Cite

Polychaetes possess a wide range of sensory structures. These form sense organs of several kinds, including the appendages of the head region (palps, antennae, tentacular cirri), the appendages of the trunk region and pygidium (parapodial and pygidial cirri), the nuchal organs, the dorsal organs, the lateral organs, the eyes, the photoreceptor-like sense organs, the statocysts, various kinds of pharyngeal papillae as well as structurally peculiar sensory organs of still unknown function and the apical organs of trochophore larvae. Moreover, isolated or clustered sensory cells not obviously associated with other cell types are distributed all over the body. Whereas nuchal organs are typical for polychaetes and are lacking only in a few species, all other kinds of sensory organs are restricted to certain groups of taxa or species. Some have only been described in single species till now. Sensory cells are generally bipolar sensory cells and their cell bodies are either located peripherally within the epidermis or within the central nervous system. These sensory cells are usually ciliated and different types can be disinguished. Structure, function and phylogenetic importance of the sensory structures observed in polychaetes so far are reviewed. For evaluation of the relationships of the higher taxa in Annelida palps, nuchal organs and pigmented ocelli appear to be of special importance.

show abstract

Section: Nuchal Organsmentioning

confidence: 97%

Sense organs in polychaetes (Annelida)

Purschke

2005

Hydrobiologia

151

View full text Add to dashboard Cite

show abstract

“…Apart from the shape, differences also exist in the first appearance of the dorsal ciliated organs. Jelsing (2002) stated that the dorsal Fig. 12 Relationship between size of specimens (width in millimetres) and number of neuropodial hooded hooks in Spio species from the North Sea and the Baltic Sea (Müller, 1776), North Sea.…”

Section: Discussionmentioning

confidence: 98%

A contribution to the taxonomy of Spio (Spionidae, Polychaeta, Annelida) occurring in the North and Baltic Seas, with a key to species recorded in this area

2010

View full text Add to dashboard Cite

In order to resolve taxonomic problems known from literature and diagnostic practices, Spio species currently recognised in the North Sea and the Baltic Sea have been re-examined. Spio species recorded in the area of interest are S. decoratus, Spio cf. filicornis, S. goniocephala, S. martinensis, and S. armata. Spio decoratus is restricted to the North Sea, whereas S. armata occurs only in the Baltic Sea. Revised descriptions with illustrations and notes on the distributions, as well as remarks on size-dependent differences of characters, are presented for all species. Specimens of Spio from the North and Baltic Seas, which are assigned to S. filicornis based on current taxonomic literature, exhibit significant morphological differences, and are here regarded as two different species. A definite assignment of specimens from the two morphological distinct groups to one of the known Spio species was impossible based on the material available. The significance of diagnostic characters used for the identification of Spio spp. is discussed. An identification key to Spio species found in the investigation area is provided.

show abstract

“…In several species of Spionidae, the paired nuchal organs are seen on both sides of a bulging unpaired area, the caruncle, extending caudally from the prostomium (Jelsing, 2002(Jelsing, , 2003. However, in L. bahusienses the nuchal organs are more or less incorporated into the caruncular tissue.…”

Section: Discussionmentioning

confidence: 99%

Ultrastructure of the extensively developed nuchal organs of Laonice bahusiensis (Annelida: Canalipalpata: Spionidae)

Jelsing

Eibye‐Jacobsen

2009

Journal of Morphology

Self Cite

View full text Add to dashboard Cite

The nuchal organs of annelid Laonice bahusiensis (Spionidae) from northern Europe have been studied using scanning and transmission electron microscopy. L. bahusiensis is the first spionid species in which extensively developed, continuous nuchal organs are described. The nuchal organs of this genus are the longest known among polychaete annelids. They consist of paired double bands extending from the prostomium on a mid-dorsal caruncle for about 24-30 setigers. Their microanatomy corresponds to the general structural plan of nuchal organs: there are ciliated supporting cells and bipolar sensory cells with sensory cilia traversing an olfactory chamber. The organs are overlaid by a secondary paving-stone-like cover and innervated by one pair of longitudinally elongated nuchal nerves. These findings clearly favor the hypothesis that the paired, extensively developed ciliated structures found in some Spionidae are homologous with the prostomial nuchal organs characteristic of polychaete annelids.

show abstract

Ultrastructural investigations on the cephalic and metameric nuchal organs of Spio cf. filicornis (Polychaeta, Spionidae)

Cited by 13 publications

References 16 publications

Sense organs in polychaetes (Annelida)

Sense organs in polychaetes (Annelida)

A contribution to the taxonomy of Spio (Spionidae, Polychaeta, Annelida) occurring in the North and Baltic Seas, with a key to species recorded in this area

Ultrastructure of the extensively developed nuchal organs of Laonice bahusiensis (Annelida: Canalipalpata: Spionidae)

Contact Info

Product

Resources

About